Vortex flowmeters are used in the industrial process control field for measuring a flow rate of a fluid. Vortex flowmeters are typically inserted in a flow pipe or conduit that carries the fluid to be measured. Industry applications include petroleum, chemical, pulp and paper, mining and materials, oil and gas. The operating principal of a vortex flowmeter is based on a phenomenon of vortex shedding known as the von Karman effect. As fluid passes a bluff body, it separates and generates small eddies or vortices that are shed alternately along and behind each side of the bluff body. These vortices cause areas of fluctuating flow and pressure that are detected by a sensor. The frequency of vortex generation is essentially proportional to fluid velocity.
Fluid flow past non-uniformities that are downstream from the sensor can generate flow noise that couples back to the sensor. The flow noise reduces the accuracy of the flow measurement and presents a problem that limits performance of the flowmeter.